1, calling intercom
2, press button, open the door
3, see the entrance
4. Call back to entrance

Scope of application: match to all-the monitors in four wire system
Case: plastic
Installation method: surface mounting
Screen: 7?/st1:chmetcnv>LCD

Specification:
Working Voltage: AC110V-140V
Working Current:B/W=600mA Color =400mA
Wiring: 4 wires
Communication Duration: 45-90sec
Ambient Humidity:45%-95%
Video Output:15625HZ 1.0Vp-p75Ohms PAL or NTSC
Product Dimension:280*140*55MM
Inner Package:285*206*70MM
Carton Size:600*450*240MM 12 in a carton